The power and propulsion section of Orbital ATK’s next Cygnus supply ship, featuring new solar panel and fuel tank designs, arrived at NASA’s Kennedy Space Center in Florida on Wednesday to be joined with a cargo module for a Dec. 3 launch to the International Space Station.

With its liftoff just 18 days away to deploy a new Global Positioning System satellite, stacking of the next United Launch Alliance Atlas 5 rocket began Monday at the vertical assembly building outside Complex 41.

Orbital ATK plans to launch its next two commercial resupply missions to the International Space Station on Atlas 5 rockets, grabbing a launch slot in March after a next-generation U.S. weather satellite was delayed, industry officials said.